Linear seat-back recliner mechanism

ABSTRACT

The linear seat-back recliner mechanism enables pivotal rotation of a seat back relative to a seat cushion in accordance with occupant request. The mechanism comprises an elongated recliner rod, an actuator mechanism, and a spring unit. The actuator mechanism is secured to the seat cushion. The recliner rod is pivotally retained relative to the seat back and slidingly engaged through the actuator mechanism, the spring unit being positioned between the seat-back frame and the actuator mechanism. The spring unit is disposed about the recliner rod, and includes an inner elongated compression spring nested within an outer elongated compression spring.

FIELD OF USE

The present invention involves a linear seat-back recliner mechanism and, more particularly, a recliner mechanism that enables the adjusting and retaining the angular position of a seat back relative to a seat cushion in a motor vehicle, an aircraft, watercraft, home recliner, or other seating applications.

BACKGROUND OF THE INVENTION

There are many configurations for linear seat-back recliner mechanisms, including:

U.S. Pat. No. 5,618,083 (Martone et al.) which discloses a linear seat-back recliner mechanism that is infinitely adjustable. The mechanism includes an elongated actuator rod that cooperatively engages with an actuator through interlocking serrations that enhance the gripping power of the mechanism.

U.S. Pat. No. 5,338,100 (Rees) which discloses a high-strength seat frame recliner having a pair of seat track assemblies. The seat-back frame is cooperatively engaged with the lower recliner structure to insure compressive loading when subjected to frontal forces during impact, while permitting entry into the back seat for a two-door vehicle.

U.S. Pat. No. 5,280,999 (Jones et al.) which discloses a manually actuated recliner mechanism having an infinitely-variable lead screw with a helical screw thread. A mechanism locks the lead screw to prevent unwanted rotation. Upon the selective release of the lock mechanism, axial forces applied to the lead screw enable angular adjustment of the seat back.

U.S. Pat. No. 5,199,764 (Robinson) which discloses a power recliner including a master and a slave recliner mechanism. An integrally powered motor is mounted onto the master recliner mechanism. Each recliner mechanism includes a threaded recliner rod which prevents the forward withdrawal from the master recliner mechanism.

U.S. Pat. No. 5,052,752 (Robinson) which discloses an infinitely adjustable recliner that enables continuously variable seat-back angular positioning. The mechanism includes a threaded recliner rod disposed within a coil spring. One end of the spring engages the housing assembly and the other end of the spring engages a secure projection of the rod. The spring urges the seat back to an upright position when the recliner mechanism is in a released state.

U.S. Pat. No. 4,898,424 (Bell) which discloses a spring-loaded latch mechanism that controls the rotational repositioning of the seat back relative to the seat frame. The mechanism includes an elongated rod that is disposed within an elongated compression spring. The rod has a pair of abutment shoulders that engage the ends of the spring and inhibit the axial movement of the shoulders toward the latch frame but yield to forces transmitted by the occupant of the seat.

Long compression springs buckle when they are compressed. A guide rod is often inserted into the spring to prevent lateral movement of the spring. When the rod includes surface variations, such as steps, or teeth, noise occurs when the inner surface of the spring travels across these surface variations.

What is needed is an improved linear seat recliner that can be readily modified to accommodate various loading requirements by using multiple nested springs that can be positioned relative to each other according to operational demands.

What is needed is an improved linear seat recliner that uses conventional springs that are readily available that are low cost items, and that are easily assembled.

What is needed is an improved linear seat recliner having a relatively simple design that is compatible with a two-sided configuration, involving both a master and a slave unit having the same or similar parts in each unit that will simplify assembly and reduce costs.

What is needed is an improved linear seat recliner using springs that can be used in a wide variety of load environments that are readily interchangeable but will minimize buckling, and are essentially silent.

What is needed is an improved spring configuration for use with linear seat-back recliner mechanisms that eliminates tangling of the compression springs when they are transported in bulk.

What is needed is an improved linear seat recliner that is applicable to manual and power mechanisms, to light duty and heavy duty vehicles in additon to passanger cars, and provides high output

What is needed is an improved linear seat recliner that is easy to assemble, that is reliable, that is lightweight, that can be adapted for use in motor vehicles, aircraft, watercraft, recliners, or any other similar seating application.

SUMMARY OF THE INVENTION

Briefly, the linear seat-back recliner mechanism of the present invention enables pivotal rotation of a seat back relative to a seat cushion, and will lock the seat back in position relative to the seat cushion in accordance with occupant demand.

The mechanism preferably comprises a master and a slave unit connected by either a power cable or torque transmission means. The master and the slave unit each comprise an elongated recliner rod, an actuator mechanism, and a spring unit.

The elongated recliner rod is pivotally retained relative to the seat back and a seat-back frame, and the rod extends through an actuator mechanism. The spring unit is disposed on the recliner rod between the actuator mechanism and the pivotal attachment to the seat-back frame.

A variety of spring units may be used to provide the necessary tensile forces. The spring unit may comprise two or more compression springs nested one inside the other. The spring unit may comprise a spring having reduced diameter coils that sandwich the larger diameter coils. The spring unit may also comprise larger diameter coils that sandwich smaller diameter coils.

For a more complete understanding of the linear seat-back recliner mechanism of the present invention, reference is made to the following detailed description and accompanying drawings in which the presently preferred embodiments of the invention are shown by way of example. As the invention may be embodied in many forms without departing from spirit of essential characteristics thereof, it is expressly understood that the drawings are for purposes of illustration and description only, and are not intended as a definition of the limits of the invention. Throughout the description, like reference numbers refer to the same component throughout the several views.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a front seat assembly of a vehicle which includes a first embodiment of the linear seat-back recliner mechanism of the present invention;

FIG. 2 is an assembly view of an actuator mechanism as used in the linear seat-back recliner mechanism of FIG. 1;

FIG. 3 is a partial elevational view of the actuator mechanism of FIG. 2 when in the seat-back reclined position;

FIG. 4 is a partial elevational view of the actuator mechanism of FIG. 3 when in the seat-back up position;

FIG. 5A is a plan view of the linear seat-back recliner mechanism of FIG. 1 having a configuration using both a master and a slave actuator mechanism joined by a pivot rod for transferring torques;

FIG. 5B is an isometric view of another embodiment having a master and a slave actuator mechanisms joined by a power cable;

FIG. 6 shows a compression spring in the expanded condition with respect to a recliner rod having surface irregularities, the spring and the recliner rod being components of the linear seat-back recliner mechanism of the present invention;

FIG. 7 shows the compression spring of FIG. 6 in the compressed condition with respect to the recliner rod having surface irregularities;

FIG. 8 shows a variation of the spring unit relative to a recliner rod, the spring and the recliner rod being components of the linear seat-back recliner mechanism of the present invention;

FIG. 9 shows another variation of the spring unit relative to a recliner rod, the spring and the recliner rod being components of the linear seat-back recliner mechanism of the present invention; and

FIG. 10 shows yet another variation of the spring unit relative to a recliner rod, the spring and the recliner rod being components of the linear seat-back recliner mechanism of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, FIG. 1 discloses a vehicle seat assembly 15! incorporating a linear seat-back recliner mechanism 10! in accordance with the present invention. The seat assembly 15! is of the type conventionally installed in the front passenger's compartment of motor vehicles. The assembly 15! includes a seat back 12! and a seat cushion 14!, with the linear seat-back recliner mechanism 10! enabling the angle between the seat back 12! and the seat cushion 14! to be variably controlled in accordance with occupant demand.

A seat-back frame 13! is anchored to the seat back by conventional fasteners which enables the seat back 12! to rotate pivotally to a desired position relative to the seat cushion. The seat-back frame 13! is made of a relatively rigid material and is suitably configured to provide stable pivotal rotation upon the actuation of the recliner mechanism 10!.

The seat-back recliner mechanism 10! preferably comprises a master and a slave unit 10A and 10B! cooperatively engaged by either a mechanical means 17A! as seen in FIG. 5A, or a power cable 17B! as seen in FIG. 5B. The master-slave connection 17! enables torque to be transmitted from the master unit 10A! to the slave unit 10B!. The master unit 10A! and the slave unit 10B! each comprise an elongated recliner rod 20!, an actuator mechanism 100!, and a spring unit 30!. As is apparent from FIGS. 5A and 5B, the master unit 10A! includes many components that are common with or mirror images of those components on the slave unit 10B!. Also, the principles of the present invention are applicable to dual actuator mechanisms involving two units, only one of which has a spring unit providing the seat-back return force.

One end 24! of the elongated recliner rod 20! is pivotally retained relative to the seat back 12! and a seat-back frame 13!. The recliner rod 20! extends through the actuator mechanism 100!. Axial movement of the recliner rod 20! through the actuator mechanism and a limited range defines a range of angular movements of the seat back 12! relative to the seat cushion 14!. The actuator mechanism 100! releases the seat back 12! enabling a repositioning of the seat back 12! relative to the seat cushion 14! and enables the seat back 12! to lock in position relative to the seat cushion 14!.

FIG. 2 discloses the actuator mechanism 100! which is disposed within an actuator housing 102!, which is generally rectangular and encases a pair of metal side plates 120A and 120B!, a pair of plastic spacers 140A and 140B! with conventional fasteners (not shown) and rivet 160!. The plates 120A and 120B! and spacers 140A and 140B! include a plurality of apertures 144! for cooperative engagement with rivets (not shown) corresponding elongated slots sized to receive a pawl pin 118!. The elongated slots define a vertically extending cam slot 142!. Each rivet is cooperatively engaged through an aperture 144! to secure the spacers 140A and 140B! to the side plates 120A and 120B!. A rivet 160! engages through an aperture 122! and is a mounting tube for receiving a pin 106! to rotatably mount the mechanism to the seat frame. Each spacer 140A and 140B! has two faces and two recesses. The cylindrical recess 147A! formed between the spacers 140A and 140B! enables the recliner rod 20! to slide through during repositioning of the seat back 12!. Each first face is abutted whereby the first recesses define a generally inverted T-shaped cavity 146!, having a pair of vertical sidewalls that define a channel for receiving the pawl 150!. Each side plate 120A and 120B! abuts one respective second face whereby the second recesses define a generally wedge-shaped cavity 148! having radial sidewalls 147 and 149! and which receives one cam plate. A bore is defined through the side plates 120A and 120B! and spacers 140A and 140B! by respective apertures therein being aligned, the bore being sized to receive a pivot rod 110A!.

One end of the spring unit 30! abuts a flat portion 24! of the recliner rod 20! and the other end of the spring unit 30! abuts the actuator housing 102!. The spring unit 30! inhibits axial movement of the seat back toward the actuator housing 102!, but yields to forces transmitted thereto by the occupant rotating the seat back.

The cam plates 130A and 130B! are wedge-shaped, generally flat, and include an elongated slot at its narrowest apex to define a keyway 136!, an arcuate slot 132! defining a cam follower surface 134! and a notched spring retainer flange 138! extending upwardly therefrom so as to extend outwardly of the side plate it confronts. The cam plates 130A and 130B! are adapted to rotate between 147 and 149! defined by the cavity 148! into which it is fit. The cam follower surface 134! has arcuate first and second portions spaced radially outward from keyway 136! to engage and thereby drive pawl pin 118!.

The pawl 150! is a generally inverted T-shaped. The bottom portion of the pawl 150! has teeth 154! that cooperatively engage teeth 22! on the recliner rod 20!. In turn, the actuator mechanism is pivotally secured to the seat cushion.

The body portion of the pawl 150! is adapted to reciprocate in the channel in a vertical plane relative to the recliner rod 20!. A cylindrical aperture 156! in its body portion is aligned with the oval shaped cam slot 142! and is sized to receive pawl pin 118!.

Pivot rod 110A! has a flat 112! and extends through bore 122!. The cross section of the rod 110A! defines a key which fits in the keyways 136! of cam plates 130A and 130B! to prevent rotation of the cam plates 130A and 130B!. The pivot rod 110A! has opposing end portions 113 and 115! each respective end portion extending outwardly from one respective side plate. Rod end 113! extends away from the seat and being connected to manually operated handle 116! and rod end 115! extends toward the seat.

A coil torsion spring 118A! is adjacent each side plate and fits above pivot pin 110A!. Each torsion spring 118A! has one end 117! abutting a respective side flange 128! in side plate 120A! and its other end 119! being received in a notch of the cam plate spring retainer flange 138!. The torsion springs 118A! inhibit rotation of the respective cam plates 130A and 130B!.

Pawl pin 118! has a circular cross section and extends through aperture 156! in pawl 150!, and through the squared cam slots 142! formed in side plates 120A and 120B! and spacers 140A and 140B!. A cam slot 142! restrains a pawl pin 152!, for vertical movement relative to the actuator as a result of rotation of the cam plates 130A and 130B! by the pivot rod 110A!. Pawl pin 118! fits into the arcuate slot 132! and is engaged by cam follower 134!. Rotation of the cam plates 130A and 130B! cause the follower surfaces to drive the pin vertically relative to the cam slot 142!, removing engagement between the pawl teeth 154! with the teeth 22! on the recliner rod 20!.

The actuator mechanism 100! may also be similar either to the mechanism shown in U.S. Pat. No. 4,898,424 or U.S. Pat. No. 5,052,752, both Patents being incorporated by reference into this specification.

A variety of spring units 30! may be used to provide the necessary tensile forces. FIG. 9 depicts another embodiment of the spring unit 30C! of the present invention comprising two compression springs 32A and 32B! nested one inside the other. FIG. 10 depicts another embodiment of the spring unit 30D! of the present invention comprising three compression springs other 32A, 32B, and 32C! nested one inside the other. The spring unit 30! may comprise a spring having reduced diameter coils that sandwich the larger diameter coils (see FIGS. 6 and 7). FIG. 8 shows another embodiment of a spring unit 30B! and recliner rod 20! of the present invention, wherein one end of the spring unit 32! has a reduced coil and abuts one end 24! of the recliner rod 20! that is secured to the seat back. The spring unit 30! may also comprise larger diameter coils that sandwich smaller diameter coils. And finally the spring unit 30! may comprise multiple nested springs, whereby the inner spring has coils of varying diameters.

An elongated cylindrical recliner rod 20! is disposed inside the spring units to prevent buckling. The recliner rod 20! includes a flat end 22! that is pinned to the seat-back frame 13!, which enables rotation of the seat back 12! relative to the seat cushion 14!.

The spring unit 30! comprises one or more annular compression springs disposed between the flat end 22! of the recliner rod 20! and the actuator mechanism 100!, as hereinafter described.

The spring unit 30! is fully compressed when the seat back 12! is in the extreme reclined position. When moved forward from the fully reclined position the actuator releases engagement and the spring unit 30! forces the seat back 12! forward moving the recliner rod 20! upwardly.

It is appreciated that significant advantage can be achieved by combining multiple springs, since it will require a higher spring force to achieve the same deflection as can be achieved with a single spring in the same envelope or package. FIG. 9 shows a spring unit having dual nested springs, and FIG. 10 shows a spring unit having triple nested springs.

When two or more springs are nested together, the slopes of the coils of adjacent springs are preferably in opposite directions. The inner spring coils may have smaller and larger diameter coils, to minimize noise during compression or to eliminate the need for end stops or washers as discussed below. The nested compression springs are fully compressed in the reclined position, and are in any one of many partially compressed conditions when the seat back is in all other positions.

Also, open coil springs often become entangled together when transported in bulk. This tangling can be eliminated by nesting and securing two or more springs together. The nested springs are secured together by twisting a smaller diameter spring into a larger diameter spring that has reduced end coils. The springs will not become entangled if the direction of the wind is opposite in adjacent springs.

Noise involving the spring unit 30! can be significantly reduced by varying the diameter of the springs at selected locations at one or more locations along the length of the spring. The recliner rod 20! may include surface irregularities 22!, such as notches or teeth as seen in FIGS. 6 and 7. This feature is especially significant if multiple nested springs are used, since the inner spring 32A! serves as a guide for the outer spring 32B!.

As used herein, the term "mean diameter" is the outer diameter of the coil less the wire diameter. A spring having a lower spring rate is used when a larger wire diameter is used in conjunction with a greater mean diameter. When there is not enough room for a conventional compression spring, increased spring outputs can be achieved at intermediate positions by using a spring 32A! with a lower spring rate. This can be accomplished by using a spring 32A! having reduced end coil diameters, and a larger average mean diameter.

By using a spring having reduced coils 34A! on the ends sandwiching larger diameter coils 34B!, it becomes unnecessary to use components such as flat washers or stops.

As shown in FIG. 1, the master unit 10A! includes a handle 116! for manual operation, generally positioned on the outboard side of the driver's seat. If the driver and the front-seat passenger have bucket seats or the like, each seat would include a handle 116! on the respective outboard sides thereof.

While the embodiment shown herein utilizes a manual actuator mechanism 100!, the principles of this invention are equally applicable to a power actuator mechanism, or a dual actuator mechanism. Further, it is appreciated that in some seats, in many applications only a single linear seat-back recliner mechanism 10! may be needed rather than using a master and a slave unit 10A and 10B!.

It is evident that many alternatives, modifications, and variations of the linear seat-back recliner mechanism 10! of the present invention will be apparent to those skilled in the art in light of the disclosure herein. It is intended that the metes and bounds of the present invention be determined by the appended claims rather than by the language of the above specification, and that all such alternatives, modifications, and variations which form a conjointly cooperative equivalent are intended to be included within the spirit and scope of these claims. 

I claim:
 1. A linear seat-back recliner mechanism enabling pivotal rotation of a seat-back relative to a seat cushion in accordance with occupant demand, the mechanism comprising:an elongated recliner rod adapted for pivotal retention with the seat-back and a seat-back frame, the recliner rod extending through an actuator housing; an actuator mechanism disposed within the actuator housing, the actuator mechanism adapted to release the seat-back enabling a repositioning of the seat-back relative to the seat cushion in accordance with occupant demand, the actuator mechanism adapted to lock the seat-back into position relative to the seat cushion in accordance with occupant demand; and a spring unit disposed about the elongated recliner rod, the spring unit comprising an outer elongated compression spring having a cavity disposed therein, and an inner elongated compression spring having a smaller diameter than the outer spring, the inner spring being nested within the cavity of the outer spring.
 2. A linear seat-back recliner mechanism enabling pivotal rotation of a seat-back relative to a seat cushion in accordance with occupant demand, the mechanism comprising:an elongated recliner rod adapted for pivotal retention with the seat-back and a seat-back frame, the recliner rod extending through an actuator housing, the elongated recliner rod having surface irregularities; an actuator mechanism disposed within the actuator housing, the actuator mechanism adapted to release the seat-back enabling a repositioning of the seat-back relative to the seat cushion in accordance with occupant demand, the actuator mechanism adapted to lock the seat-back into position relative to the seat cushion in accordance with occupant demand; and a compression spring being disposed about the elongated recliner rod, the spring having smaller diameter coils and larger diameter coils, the spring having a first and a second position relative to the seat-back frame, the larger diameter coils being adjacent the surface irregularities on the recliner rod when the seat-back is in the first position, the larger diameter coils being adjacent the surface irregularities on the recliner rod when the seat-back is in the second position.
 3. A linear seat-back recliner mechanism enabling pivotal rotation of a seat-back relative to a seat cushion in accordance with occupant demand, the mechanism comprising:an elongated recliner rod adapted for pivotal retention with the seat-back and a seat-back frame, the recliner rod extending through an actuator housing; an actuator mechanism disposed within the actuator housing, the actuator mechanism adapted to release the seat-back enabling a repositioning of the seat-back relative to the seat cushion in accordance with occupant demand, the actuator mechanism adapted to lock the seat-back into position relative to the seat cushion in accordance with occupant demand; and a compression spring disposed about the recliner rod, the compression spring including a plurality of first coils having a first spring diameter and a plurality of second coils having a second spring diameter, the first coils sandwiching the second coils.
 4. The linear seat-back recliner mechanism of claim 3, wherein the first coils have a larger spring diameter than the second coils.
 5. The linear seat-back recliner mechanism of claim 3, wherein the first coils have a smaller spring diameter than the second coils.
 6. A linear seat-back recliner mechanism enabling pivotal rotation of a seat-back relative to a seat cushion in accordance with occupant demand, the mechanism comprising:an elongated recliner rod adapted for pivotal retention with the seat-back and a seat-back frame, the recliner rod extending through an actuator housing; an actuator mechanism disposed within the actuator housing, the actuator mechanism adapted to release the seat-back enabling a repositioning of the seat-back relative to the seat cushion in accordance with occupant demand, the actuator mechanism adapted to lock the seat-back into position relative to the seat cushion in accordance with occupant demand; and a spring unit which includes at least one compression spring, the spring unit being disposed about the recliner rod, the spring unit comprising a plurality of inner coils having an inner mean diameter and a plurality of outer coils having an outer mean diameter, the inner coils being disposed interior to the outer coils, the inner mean diameter being different from the outer mean diameter.
 7. The linear seat-back recliner mechanism of claim 6, wherein two compression springs are nested one inside the other, the inner spring having a substantially uniform diameter.
 8. The linear seat-back recliner mechanism of claim 6, wherein two compression springs are nested one inside the other, the inner spring having a plurality of first coils having a larger spring diameter and a plurality of second coils having a smaller spring diameter, the larger coils sandwiching the smaller coils.
 9. The linear seat-back recliner mechanism of claim 6, wherein two compression springs are nested one inside the other, the inner spring having a plurality of first coils having a smaller spring diameter and a plurality of second coils having a larger spring diameter, the smaller coils sandwiching the larger coils.
 10. The linear seat-back recliner mechanism of claim 6, wherein two compression springs are nested one inside the other, the outer spring having a plurality of coils having a smaller spring diameter disposed at one end and a plurality of coils having a larger spring diameter disposed at the other end, the inner spring having coils of substantially uniform diameter.
 11. The linear seat-back recliner mechanism of claim 6, wherein more than two compression springs are each nested one inside the other.
 12. The linear seat-back recliner mechanism of claim 6, wherein one compression spring having larger diameter coils is sandwiched between smaller diameter coils, one end of the compression spring with the reduced diameter coils abutting one end of the recliner rod that is secured to the seat-back.
 13. The linear seat-back recliner mechanism of claim 6, wherein one compression spring having larger diameter coils is sandwiched between smaller diameter coils, the middle of the spring unit having the larger diameter coils being adjacent to notches in the recliner rod to reduce noise.
 14. The linear seat-back recliner mechanism of claim 6, wherein one compression spring having smaller diameter coils is sandwiched between larger diameter coils. 